Fish egg incubator

ABSTRACT

A fish egg incubator apparatus is provided which solves the problems of containing the fish eggs while gently circulating water around them for hatching purposes and subsequently transferring the larvae to other containers. The incubator includes a tubular water permeable container connected at each respective end with one of a pair of annular support rings and having a buoyant collar affixed to one of the support rings for floating the container in a body of water with the water permeable wall disposed below the water level therein. A funnel structure and a valve are provided at the bottom of the assembly for alternatively connecting the same to a submersible pump whereby water may be gently pumped into the interior of the tubular container or, upon hatching of the eggs, for closing the valve and slipping a tubular jacket having one closed end over the assembly from the bottom whereby the entire assembly may be lifted from the water and transferred to another area without disturbing the larvae.

United States Patent Lewis [45] Aug. 15, 1972 [54] FISH EGG INCUBATOR[57] ABSTRACT [72] Inventor: Raymond H. Lewis, West Palm A fish eggincubator apparatus is provided which Beach, Fla. solves the problems ofcontaining the fish eggs while Assignee g p y Maricunure Indus gentlycirculating water around them for hatching purtries, lnc., RivieraBeach, Fla.

[22] Filed: Sept. 17, 1970 [21] Appl. No.: 73,103

[52]- US Cl "119/3 [51] int. Cl. .,A0lk 61/00 [58] Field 0i Search..'.....1 19/3, 2, 4, 5; 43/55, 56

[56] References Cited UNITED STATES PATENTS 3,584,602 6/1971 Sfasio ..119/3 3,478,463 11/1969 Ruter 43/55 2,674,825 4/1954 Rice ..43/56 180,0857/1876 Wilmot ..1 19/3 680,838 8/1901 Bourgeois ..1 ..l19/3 PrimaryExaminen-Hugh R. Chamblee AttorneyOblon, Fisher & Spivak poses andsubsequently transferring the larvae to other, containers. The incubatorincludes a tubular water permeable container connected at eachrespective end with one of a pair of annular support rings and having abuoyant collar afiixed to one of the support rings for floating thecontainer in a body of water with the water permeable wall disposedbelow the water level therein. A funnel structure and a valve areprovided at the bottom of the assembly for alternatively connecting thesame to a submersible pump whereby water may be gently pumped into theinterior of the tubular container or, upon batching of the eggs, forclosing the valve and slipping a tubular jacket having one closed endover the assembly from the bottom whereby the entire assembly may belifted from the water and transferred to another area without disturbingthe larvae.

6 Claims, 2 Drawing Figures PATENTEDAIJ: 15 m2 mvsu'ron RAYMOND IH.LEWIS ATTORNEYS FISH EGG INCUBATOR BACKGROUND OF THE INVENTION.

flow to cascade successively downward therethrough to keep the eggstherein immersed in water and provide& uniform circulation of water overthe eggs, and which further are provided with flotation cells forpermitting the same tray to be removed from the stack and floated in arearing pond or other body of water. Heretofore, however, the deviceshave generally included both perforate top and bottoms for permittingfree ingress and egress of water over all areas'therein, and therelative buoyancy imparted by the flotation means has generally beensuch that the tray floats with its major portion submerged so that theentire contents of the tray are immersed.

Until recently, the artificial propagation and raising of fish hasgenerally concerned only the various species of fresh water fish andthese fish egg incubating devices accordingly have been designedprimarily to accommodate the characteristics of fresh water fish, withlittle, if any, consideration being given to design characteristicswhich might be more beneficial in the propagation of salt water,estuarine, or marine fish, as they may more broadly be classified. Anever-increasing demand, however, for greater supplies of food fishes andthe healthful protein which comes therefrom has now caused this industryto extend its practice to include the marine varieties. Thus, incontrast to certain species of fish which live and/or breed in freshwater, such as, for example, trout and salmon, and produce demersaleggs, which are negatively buoyant and sink to the bottom of the freshspawning waters, many species of marine fish, such as, for example, thehighly flavorful pompano, produce eggs which are buoyant, so that theyfloat near the surface. This is the case because the larva of thepompano, as well as many other species of marine fish, is a pelagicplankton feeder, whereby it is essential for its survival that it behatched in the proper feeding environment near the surface.

It has been found, in pompano mariculture and the like, since theincubation tank must provide a closely controlled environment favorablefor embryo development, including careful control of light, temperatureand salinity, that a special tank should be used for this incubationstage and, upon hatching, the larvae may be transferred toanother tankwhich is intended to optimize the larvae rearing conditions. This phaseis perhaps the most critical in the production process, however, sinceonce the eggs have hatched, the larvae,

which are quite small and delicate, are quite vulnera-' ble, so thatgreat care must be exercised in transferring by presently knownincubator devices and fish farming" techniques.

SUMMARY OF THE INVENTION Accordingly, the present invention is broadlydirected to improvements in the form and construction of fish eggincubators to overcome certain difficulties and shortcomings of existingincubators which limit the benefits obtainable therefrom, especially inthe propagation and raising of certain marine fish.

Thus, it is an object of the present invention to provide an improvedfish egg incubator wherein the fish eggs are gently circulated, withwater and from which the resulting larvae may be easily and gentlytransferred to other containers.

Another object of the present invention is to provide an improvedapparatus for hatching the eggs of certain marine fish and transferringthe same safely to other containers.

The foregoing and other objects are achieved, according to one aspect ofthe present invention, by a specially designed incubator for confiningan egg batch which consists of a hollow tube of water permeable materialfastened at one end to the wide end of a funnel structure and providedwith a flotation collar of a buoyant material, such that the incubatorfloats upright in an incubation tank, with the open upper end of thetube just above the water surface and the funnel outlet toward thebottom of the tank. For circulation, a submersible pump in the tankdelivers water through a tube connected to the funnel bottom and upwardinto the floating incubator, through the walls of which the water freelycirculates back into the tank. A valve in the funnel bottom permitsclosing of the same whereupon, when the pump tubing is removed, atubular jacket having a closed end may be slipped over the incubatorfrom the bottom whereby the entire assembly may be lifted from the tank,with the incubator container still submerged in water within theconfines of the jacket, and transferred to a separate rearing tank orother body of water without disturbing the hatched eggs or larvaetherein.

BRIEF DESCRIPTION OF THE DRAWING water and shown being attached to apump for circulating water therethrough; and

FIG. 2 is a perspective view of the jacket which may be used incombination with the fish egg incubator, upon disconnecting the samefrom the pump, for transferring the incubator to another body of waterwithout disturbing the contents thereof.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now in particular toFIG. 1 of the drawing, a fish egg incubator generally indicated by thereference numeral 10, for containing fertilized eggs and keeping thesame in a given locality while providing gentle circulation of waterabout them, is shown afloat in a body of water 12. The incubatorcomprises a hollow, preferably tubular, container 14 of water permeablematerial, such as, for example, a fine nylon mesh screen, which issupported by flat annular rings 16 and 18 secured to the ends thereof.The rings 16 and 18 may be constructed from any suitable material, suchas, for example, polyvinylchloride.

A flotation collar 20 of a suitable buoyant material, such as, forexample, foamed polystyrene, is secured to the underside of the flatannular ring 16 by a suitable marine adhesive, or the like, such thatthe incubator floats upright in the water with the open end of thetubular piece 14 to which ring 16 is affixed being just above the waterlevel. The bottom of the incubator 10 is preferably formed in asubstantially funnel-like configuration and, as shown, consists of aseparate member 22 having the wide mouth end thereof attached to thelower ring 18 by a marine adhesive, or any other satisfactory manner.The lower end of the funnel-like member 22 terminates in a substantiallytubular projection 24 which is integrally formed therewith and providesa fluid communication path to the bottom of the incubator 10, or thefunnel portion 22 thereof. Disposed within the tubular projection 24 isa valve member 26 which is operable for either opening or closing thefluid communication path through the projection 24. Although it isunderstood that other materials may be used, the funnel-like structure22, tubular projection 24 and the valve 26 are preferably formed frompolyethylene.

A submersible bilge pump 30 is positioned in the body of water 12 and isconnected through a length of tygon tubing 32, or similar conduit means,to the downwardly extending projection 24 of the funnel member 22. Inuse, therefore, during the normal incubation period, the egg incubator10 floats in the water 12 at the level of the flotation collar 20, andthe viable eggs inserted into the interior thereof float on the water inthe incubator, which is continuously being exchanged with the exteriorwater through the tubular nylon mesh screen wall 14. For insuring that arelatively gentle circulation is maintained, the valve 26 is thesubmersible pump 30 attached thereto through the tubing 32.

Other configurations can obviously be developed for satisfying therequirements of the incubation stage. For example, for water circulationpurposes, the incubation tank, or body of water 12, may be provided witha manifold reservoir at some height above the water level in the tankand this manifold may be provided with one or more valved outlet pipeseach of which can be con nected by tubing to the submerged funnel outlet24 of an incubator 10. A submersible pump, such as, for example, thepump 30, in the body of water 12 may be utilized for delivering water tothe mainfold, from which it can be distributed by gravity feed via thetubing to the incubator or incubators. This alternative arrangement alsoprovides a relatively gentle circulation mechanism within the incubatorswhile allowing for adequate overall circulation rates. The main thing isplaced in an open position, whereby water may be gently pumped into theinterior of the incubator 10 by that the eggs be exposed to a relativelygentle circulation pattern which produces some stirring or motion.

Toward the end of the incubation period, when the eggs are ready tohatch, they are preferably transferred to another tank which isenvironmentally controlled to optimize the larvae survival rate. Asindicated hereinbefore, this phase is the most critical in theproduction process, since once the eggs have hatched, the larvae, whichare quite small and delicate, are quite vulnerable, so that great caremust be exercised in transferring them.

Referring now in particular to FIG. 3, there is shown a cylindricaljacket 34 constructed of a suitable material, preferablypolyvinylchloride, which is closed at one end and open at the other endand is provided with handles 36, only one of which is shown. The purposeof this jacket is to assist in transferring the larvae from theincubation tank to a rearing tank, or the like, as will be set forthhereinbelow.

The transfer of the larvae is accomplished first by turning off the pump30 and closing the valve 26 in the tubular projection 24 of theincubator 10. The tygon hose, or tubing, 32 is then removed from theprojection 24 and the jacket 34 is slipped over the incubator 10 fromthe bottom thereof, beneath the surface of the water, and the entireassembly is lifted from the water by means of the handles 36. Thus,during transfer, the incubator is positioned within the jacket 34 withsubstantially the same level of water in and surrounding it as when itwas floating in the body of water 12, whereby the larvae remainundisturbed therein. Removal of the larvae from the assembly includingthe incubator 10 and the jacket 34 is accomplished by pushing the entirestructure downward into the water whereupon, at the time the flotationcollar 20 becomes substantially level with the surface of the watertherein, the incubator 10 may be left floating in the new body of watermerely by continuing to push the jacket 34 alone further downwardly tothereby free the incubator 10 from the jacket 34. In this case, thelarvae are transferred to a new tank still being contained within theprotective confines of the incubator screening 14. On the other hand, ifit is desired to transfer the larvae to the new container and free thesame from the incubator, it is only necessary to press the flotationcollar 20 downwardly beneath the surface of the water of the newcontainer to permit the larvae therein to float to the surface andoutside the cylindrical chamber of the incubator.

Of course, the transfer could be accomplished in a single step bypressing both the cylindrical jacket 34 and the incubator 10simultaneously downward below the surface of the water of the new tank.

Obviously many modifications and variations of the present invention arepossible in light of the above teachings. It is to be understood,therefore, that within the scope of the appended claims the presentinvention may be practiced otherwise than as specifically describedherein.

What is claimed and desired to be secured by letters patent is:

1. A fish egg incubator apparatus comprising,in com bination:

a substantially tubular container having a waterpermeable wall portionand a closed bottom portion,

an inlet port in said bottom portion,

valve means in said inlet port for selectively opening or closing thesame,

a buoyant collar secured to said container for floating said containerin a body of water with said water permeable wall portion and saidclosed bottom portion thereof being submerged in said body of water andthe open top of said container being just above the surface of said bodyof water,

a submersible pump, and,

a fluid conducting conduit connected at one end of said pump anddisengageably connected at the other end with said inlet port.

2. The apparatus set forth in claim 1, wherein said buoyant collar isconstructed of foamed polystyrene.

3. The apparatus set forth in claim 1, wherein said water permeable wallof said container includes a fine nylon mesh screen forming at leastpart of the tubular wall surface thereof.

4. In combination with a fish egg incubator which includes a containerhaving a water permeable wall portion, a closed wall portion, an openend, an inlet port in said closed wall portion, valve means forselectively opening or closing said inlet port, and a buoyant member forfloating said container in a body of water with only said open endthereof being above the ,water surface in said body of water and theremaining portion being submerged,

a jacket having one open end for receiving said container when the sameis slipped over said container from the lower submerged end thereof,said jacket having handles for facilitating the manual grasping thereof.5. The apparatus set forth in claim 4, wherein said container issubstantially tubular in configuration and said jacket is a hollowcylindrical member being open at one end and closed at the other end. I

6. A fish egg incubator apparatus comprising in combination:

a container having an upper water permeable wall portion beingsubstantially tubular in configuration, a substantially funnel-shapedclosed wall portion being axially aligned with said tubular waterpermeable wall portion and being open at the wide mouth end thereof intosaid tubular wall portion, and an inlet port at the narrow mouth end ofsaid funnel-shaped closed wall portion,

valve means in said inlet port for selectively opening and closing thesame,

means for floating said container in a body of water in a substantiallyvertically oriented position with a predetermined portion thereof beingsubmerged in said body of water,

a pump, and

fluid communication means between said pump and said inlet port in thebottom of said container for selectively circulating water from saidbody of water through said closed wall portion of said container andthereinto, whereby a continuous exchange of water in the container isprovided by permitting the water therein to permeate through said waterpermeable wall portion for return to said body of water.

1. A fish egg incubator apparatus comprising,in combination: asubstantially tubular container having a water-permeable wall portionand a closed bottom portion, an inlet port in said bottom portion, valvemeans in said inlet port for selectively opening or closing the same, abuoyant collar secured to said container for floating said container ina body of water with said water permeable wall portion and said closedbottom portion thereof being submerged in said body of water and theopen top of said container being just above the surface of said body ofwater, a submersible pump, and, a fluid conducting conduit connected atone end of said pump and disengageably connected at the other end withsaid inlet port.
 2. The apparatus set forth in claim 1, wherein saidbuoyant collar is constructed of foamed polystyrene.
 3. The apparatusset forth in claim 1, wherein said water permeable wall of saidcontainer includes a fine nylon mesh screen forming at least part of thetubular wall surface thereof.
 4. In combination with a fish eggincubator which includes a container having a water permeable wallportion, a closed wall portion, an open end, an inlet port in saidclosed wall portion, valve means for selectively opening or closing saidinlet port, and a buoyant member for floating said container in a bodyof water with only said open end thereof being above the water surfacein said body of water and the remaining portion being submerged, ajacket having one open end for receiving said container when the same isslipped over said container from the lower submerged end thereof, saidjacket haviNg handles for facilitating the manual grasping thereof. 5.The apparatus set forth in claim 4, wherein said container issubstantially tubular in configuration and said jacket is a hollowcylindrical member being open at one end and closed at the other end. 6.A fish egg incubator apparatus comprising, in combination: a containerhaving an upper water permeable wall portion being substantially tubularin configuration, a substantially funnel-shaped closed wall portionbeing axially aligned with said tubular water permeable wall portion andbeing open at the wide mouth end thereof into said tubular wall portion,and an inlet port at the narrow mouth end of said funnel-shaped closedwall portion, valve means in said inlet port for selectively opening andclosing the same, means for floating said container in a body of waterin a substantially vertically oriented position with a predeterminedportion thereof being submerged in said body of water, a pump, and fluidcommunication means between said pump and said inlet port in the bottomof said container for selectively circulating water from said body ofwater through said closed wall portion of said container and thereinto,whereby a continuous exchange of water in the container is provided bypermitting the water therein to permeate through said water permeablewall portion for return to said body of water.